Concussion

Introduction

Concussions range in severity from mild to severe, but they all share one common factor — they temporarily interfere with the way your brain works. They can affect memory, judgment, reflexes, speech, balance and coordination.

Usually caused by a blow to the head, concussions don't always involve a loss of consciousness. In fact, most people who have concussions never black out. Many people have had concussions and not realized it.

Concussions are common, particularly if you play a contact sport like football. But every concussion, no matter how mild, injures your brain. This injury needs time and rest to heal properly. Luckily, most concussions are mild and people usually recover fully.

Signs and symptoms

The signs and symptoms of a concussion can be subtle and may not appear immediately. Symptoms can last for days, weeks or longer.

The two most common concussion symptoms are confusion and amnesia. The amnesia, which may or may not be preceded by a loss of consciousness, almost always involves the loss of memory of the impact that caused the concussion.

Other immediate signs and symptoms of a concussion may include:

Headache Dizziness Ringing in the ears Nausea or vomiting Slurred speech

Some symptoms of concussions don't appear until hours or days later. They include:

Mood and cognitive disturbances Sensitivity to light and noise Sleep disturbances

Head trauma is very common in young children. But concussions can be difficult to recognize in infants and toddlers because they can't readily communicate how they feel. Nonverbal clues of a concussion may include:

Listlessness, tiring easily Irritability, crankiness Change in eating or sleeping patterns Lack of interest in favorite toys Loss of balance, unsteady walking

Causes

Your brain has the consistency of gelatin. It's cushioned from everyday jolts and bumps by the cerebrospinal fluid that it floats in, inside your skull. A violent blow to your head can cause your brain to slide forcefully against the inner wall of your skull. Even the sudden stop of a car crash can bounce your brain off the inside of your skull. This can result in bleeding in or around your brain and the tearing of nerve fibers.

Risk factors

Any blow to the head can cause a concussion. Falls and traffic accidents often involve concussions, with or without other injuries. Without proper safety equipment and supervision, student athletes may be at increased risk of concussions when playing football and other contact sports. And anyone who has had a concussion in the past is at higher risk of having concussions in the future

When to seek medical advice

While most concussions get better on their own, some blows to the head can cause more serious injuries. You should seek medical advice if you have any of the following symptoms:

Prolonged headache or dizziness Vision disturbances Nausea or vomiting Impaired balance Prolonged memory loss Ringing in the ears Loss of smell or taste

Any child who has lost consciousness after a blow to the head should be seen by a doctor. Other warning signs of a potentially serious injury include persistent vomiting, seizures or a large bruise on the scalp. In general, a bruise on the front of the head is less dangerous than one on the side or back of the head.

Screening and diagnosis

Diagnosing a concussion is usually straightforward. If a blow to your head has knocked you out or left you dazed, you've had a concussion. It's more difficult, however, to determine whether the blow has caused potentially serious bleeding or swelling in your skull. Signs and symptoms of these injuries may not appear until hours or days after the injury.

Your doctor may start your evaluation with questions about the accident, then proceed to a neurological exam. This exam includes checking your memory and concentration, vision, hearing, balance, coordination and reflexes.

The standard test to assess post-concussion damage is a computerized tomography (CT) scan. A CT scanner takes multiple cross-sectional X-rays and combines all the resulting images to produce detailed, two-dimensional images of your skull and brain. During the procedure, you lie still on a table that slides through a large, doughnut-shaped X-ray machine. The scan is painless and generally takes less than 10 minutes.

Not every concussion requires a CT scan, but the test is usually done as a precaution if there's a chance your injury is more severe than your immediate condition suggests. You're more likely to need a scan if you:

Are younger than 16 or older than 64 Fell from a height of more than three feet Had a motor vehicle accident Are under the influence of alcohol or drugs Are unable to recall the accident for more than 30 minutes after it occurred Have persistent trouble with short-term memory — that is, retaining new information —

after you've completely regained consciousness Vomited Had a seizure Suffered bruises, scrapes or cuts on your head and neck Fractured your skull

You may need to be hospitalized overnight for observation after a concussion. If your doctor says it's OK for you to be observed at home, someone should check on you periodically for at least 24 hours. You may need to be awakened every two hours to make sure you can be roused to normal consciousness.

Complications

Postconcussion syndrome, a poorly understood complication, causes concussion symptoms to last for weeks or months. People who have had a concussion also double their risk of developing epilepsy within the first five years after the injury.

There also is evidence that people who have had multiple concussions over the course of their lives suffer cumulative neurological damage. A link between concussions and the eventual development of Alzheimer's disease also has been suggested.

Treatment

Rest is the best recovery technique. Healing takes time. For headaches, acetaminophen (Tylenol, others) or ibuprofen (Advil, Motrin, others) can be used. Avoid aspirin, as it can increase the risk of bleeding.